StreamOfTheSky
Adventurer
Just get the Whirling enchantment on that weapon.
It says otherwise in all other ways, it functions like the WWA feat. Why would you buy that when you have the feat already anyway? Also, the acitvation time is a mental full round action. The reason the combo I mentioned works is because WWA is a full attack action and arcane channeling can be used on a full attack action, and dervish dance lets you move between attacks of a full attack action. I don't think Whirling would work with ANY of that.
If you were implying to get that instead of WWA feat...with Dervish you require or get for free all of the prerequisites anyway, so it only really costs one feat. Why not have the feat to use all day long instead of 3/day at that point? Even if you're mid level and only have one dance/day, WWA might occasionally be useful without moving if you have a reach weapon and enlarge person.